function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;
function preloadImages() {
	if (document.images) {
		hp_10_hp_15_over = newImage("images/hp_10-hp_15_over.jpg");
		hp_12_hp_16_over = newImage("images/hp_12-hp_16_over.jpg");
		hp_15_over = newImage("images/hp_15-over.gif");
		hp_16_over = newImage("images/hp_16-over.gif");
		hp_17_over = newImage("images/hp_17-over.gif");
		hp_19_hp_22_over = newImage("images/hp_19-hp_22_over.jpg");
		hp_21_hp_17_over = newImage("images/hp_21-hp_17_over.jpg");
		hp_22_over = newImage("images/hp_22-over.gif");
		hp_23_over = newImage("images/hp_23-over.gif");
		hp_24_over = newImage("images/hp_24-over.gif");
		hp_27_hp_23_over = newImage("images/hp_27-hp_23_over.jpg");
		hp_29_hp_24_over = newImage("images/hp_29-hp_24_over.jpg");
		preloadFlag = true;
	}
}